For certain age groups, such as the elderly, or people that engage in certain dangerous activities, such as firefighters and soldiers, it is desirable to track and understand human activity automatically. For example, a person that has fallen may be injured, unconscious, etc., and needs emergency assistance. In such circumstances, relying on the person to initiate a call to a public safety access point (PSAP) (e.g., 9-1-1 emergency services, an automated emergency call center, etc.) is not practical. Moreover, even if the person is capable of placing the call, the PSAP may be located outside the geographical jurisdiction for providing emergency services. An emergency services person located at a PSAP may need to manually place a second call to the local fire station, police, or Emergency Medical Services (EMS) squad, thereby wasting precious time that could be used to save the person's life. Further, if the person is unconscious, they would not be able to relate the nature of their injuries nor their physical location.
Portable computing devices such as smart phones, personal digital assistants (PDAs), cellular phones, media players, tablet computers, and electronic readers, are becoming more prevalent. Although these portable computing devices are used for a variety of purposes such as viewing digital media, connecting to social networks, placing phone calls, etc., these portable computing devices often do not perform health monitoring functions.